Airplane foam generator

ABSTRACT

A foamable liquid is sprayed into a tubular chamber where it is thoroughly mixed into an airstream and thus foamed. From there the foam is forced into a larger chamber where it is dispersed to fall upon agricultural crops. The trailing edge of the second chamber from which the foam is discharged is readily adjustable so that the size of the globules of foam discharged is readily adjustable.

United States Patent {72] Inventor Norman I'l. Sachnllt 1035 Columbia,Houston, Tex. 77008 [21 1 Appl. No. 824,868 [22] Filed May 15, I969 [45]Patented Sept. 14, 1971 [54] AIRPLANE FOAM GENERATOR 3 Claims, 7 DrawingFigs.

[52] US. Cl. 169/15, 239/171 [51) Int. Cl A621: 35/00 [50] Field ofSearch... 239/171, I, 428.5, 310, 8, 419.5; 169/15, 2, 2 A; 244/136;222/ l 90 l 56] References Cited UNITED STATES PATENTS 2,173,568 9 1939Streif...l 239 7 2,772,061 1 1/1956 Sellers 239/171 X 2,988,343 6/1961Edwards et al. 169/15 X OTHER REFERENCES Article Titled Foam That KillsWeeds, by Charles E. Ball, published in the Farm Journal, page 26,Volume 92, Number 1 1, November, 1968.

Primary Examiner- M. Henson Wood, Jr. Assistant Examiner-Edwin D. GrantAttorney-Charles W. Coffee ABSTRACT: A foamable liquid is sprayed into atubular chamber where it is thoroughly mixed into an airstream and thusfoamed. From there the foam is forced into a larger chamber where it isdispersed to fall upon agricultural crops.

The trailing edge of the second chamber from which the foam isdischarged is readily adjustable so that the size of the globules offoam discharged is readily adjustable.

PATENTEDSEPWQH 3,604,509

- SHEET 1 OF 2 INVENTOR:

NORMAN H. SACHN I K PATENTEDSEPMISII 8,604,509 SHEET 2 0F 2 IGNINVENTOR: NORMAN H; SACHNIK AIRPLANE FOAM GENERATOR FILED June 30, I966634,551 Apr. 28, 1967 BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to dispersing agricultural chemicalsand more particularly to dispersing foam from an airplane.

2. Description of the Prior Art Today, many agricultural chemicals" orlife determinants are applied to crops. These agricultural chemicals maybe insecticides, herbicides, fertilizers, trace minerals, hormones,fungicides, pesticides, soil sterilants, etc. In commerce thesematerials are commonly called agricultural chemicals. A more descriptiveterm would be life determinant" because each of these materials has aneffect or determination on life. I.e., the fertilizers promote plantlife and the fungicides kill lower forms of plant life and theinsecticides kill animal life while the herbicides very selectively killcertain higher forms of plant life. Therefore, each of these materialshas definite determination upon some form of life; therefore, they mayall be called life determination," although in commerce they aregenerally known as agricultural chemicals. Often these chemicals aredispersed from an airplane. In present practice, these chemicals aregenerally dispersed either as a spray in a water solution or as a dustin dry form. Neither of these chemicals are generally dispersed eitheras a spray in a water solution or as a dust in dry form. Neither ofthese forms are entirely satisfactory.

There has been developed valves to be used upon spray rigs such as shownin WAHLIN, U.S. Pat. No. 2,639,194, so that the spray does not drip fromthe nozzle when the pressure is cut off.

Also, according to my previous inventions noted above, there is adistinct advantage of dispersing these chemicals in the form of foam. Itis possible to obtain better visual control upon dispersion of thechemicals and, also, it is possible to get as even or more evendistribution with less fluid carrier, reducing the amount of fluid whichmust be carried in the airplane. Since the capacity of the airplane islimited by the amount of carrier rather than the amount of activeingredient or life determinant constituent, if the ratio of activeingredient to carrier is doubled, it is possible in most cases to carrytwice as much active ingredient on any one trip. Generally, the ratio ofthe carrier to the active ingredient is high.

SUMMARY OF THE INVENTION I have invented a new foam generatorparticularly adapted to be carried on an airplane. In this particulardisclosure, a foamable fluid containing the life determinant isdispersed from a nozzle in a fan-shaped jet into a stream of air whichis flowing through a tube. The tube is designed to form a first chamberwith u particular shape designed to cause turbulence, insuring it fullmixing of the foamable fluid with the air so the foam is generated. Fromhere the foam is discharged into a second chamber, which is generally ofairfoil shape. From here the foam is discharged from the rear of theairfoil in such a way that it can be broken up into the size particlesdesired. The size of the particles in which the foam is broken up willdepend not only upon the particular chemical being sprayed, but, also,where the particular foam generator or chamber is located along the wingof the airplane. It is well known that at the tip of the wing of anaircraft, there is much more turbulence than there is other places.Therefore, it is often desirable to discharge larger globules at the tipbecause of the turbulence which will spread them wider and theturbulence itself will tend to break the globules into smaller size.

An object of this invention is to distribute agricultural chemicals orlife determinants upon crop land.

Other objects are to achieve the above with a device that islightweight, sturdy, compact, durable, simple, safe, versatile,efficient, and reliable, yet inexpensive and easy to manufacture,install operate, and maintain.

Further objects are to achieve the above with a method that is safe,rapid, versatile, lightweight, efficient, and inexpensive, and does notrequire skilled people to install, adjust, operate, and maintain.

The specific nature of the invention, as well as other objects, uses,and advantages thereof, will clearly appear from the followingdescription and from the accompanying drawing, the different views ofwhich are not necessarily to the same scale.

BRIEF DESORIPTION OF THE DRAWING FIG. I is a bottom-plan view of anairplane with an embodiment of my invention attached thereto.

FIG. 2 is a cross section through one wing showing the foam generatortaken substantially on line 2-2 of FIG. I.

FIG. 3 is a sectional view of the generator taken on line 3- 3 of FIG.4.

FIG. 4 is a top-plan view of the generator as would be seen on line 4-4of FIG. 2.

FIG. 5 is a sectional view of the generator taken on line 5- 5 of FIG.3.

FIG. 6 is a sectional view taken on line 6-6 of FIG. 3.

FIG. 7 is a sectional view taken on line 7-7 of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As the term is usedherein, life determinants" shall mean ingredients that are commonlycalled agricultural chemicals" and the term is meant to includeinsecticides, herbicides, fungicides, pesticides, soil sterilants;fertilizer, Pat. minerals, Ser. No. all other like materials which areused or may be used commercially in agriculture. Specific examples ofdifferent agricultural chemicals or life determinants are given in myprior Pat. application Ser. No. 561 ,740, filed June 30, I966.

Also as used herein, foamable liquid" means any substance which whenmixed with air will cause a foam. Such substances are well known and arecommonly used in fire fighting and in aerosol containers for such use asshaving. Typically they contain surfactants and water as well as foamingagents which tend to give the foam body.

I prefer to use a surfactant which lowers the surface tension of thewater inasmuch as it has beneficial effects at the time the foamcontacts growing plants, as more fully explained in my prior Pat.application Ser. No. 561,740, filed June 30, I966. Typical examples ofmixtures used to obtain foam are noted in that patent application.Furthermore, it is apparent that the foaming agent, surfactant and otheringredients must be compatible with the life determinant used.

Referring more particularly to FIGS. 1 and 2, the invention isparticularly adapted to airplane 10. The airplane includes wings I2 andpropeller 14. A vortex will result from each of the tips I3 of the wingsI2. This vortex has two effects: one, it will tend to reduce the size ofthe foam globules in this area; two, it will carry globules dispersednear the tip 13 over a wider area than otherwise. Also, there will be avortex resulting from the plane s propeller I4. These vortices and thecreation of them are well understood to those skilled in theaeronautical arts and are important in the distribution of agriculturalchemicals or life determinants from airplanes because it is necessary toadjust the amounts of materials distributed from each of the differentpoints along the wings l2 and also the size of the particles distributedfrom each of the points along the wing as they might be involved in thetip vortex or the propeller vortex.

The airplane 10, in a customary manner, carries tank 16 containing afoamable liquid and the life determinants or agricultural chemicals.(Schematic FIG. 3.) From the tank 16, the chemicals are pumped throughpump 18, thereby placing them under pressure in the supply boom 20. Thesupply boom is in the form of a pipe which is attached to the wing 32 bya plurality of struts 22. Although the pump 18 could be drivenmechanically from the airplane engine, it has been illustrated as beingwind driven by propeller 24. Constant pressure regulating valve 26 iscombined with a manual cutoff valve so that the pilot ofthc airplane mayturn on and off the flow of the foamable liquid from the pump 18 to theboom 20. Relief line 25 returns excess liquid from the valve 26 to thetank 16.

A plurality of nondrip spray nozzles 28 are fluidly and structurallyconnected to the boom 20. Spray nozzles 28 perform three functions.First: by the use of adjustment screw 30, they regulate the rate offoamable fluid flow through the nozzle. Second: the nozzles have eithera pressure flow through them or they are shut off without drip. Third:the nozzles spray the foamable liquid into an airstream. Spray nozzlesof this type are well understood, i.e., WAHLlN, US. Pat. No. 2,639,194shows one without the screw 30. The nozzle 28 has a distinctive spraydistributor 32 to obtain a fan-shaped or conicshaped distribution of theliquid throughout the airstream so that there is a good distribution ofthe foamable liquid with the arr.

Foam chamber or generator 34 is attached by spider 36 to the spraynozzle 28. The foam generator has a front tubular section 40 which hasmouth 38 which is facing the front of the airplane so that the mouthbeing flared out acts as an airscoop to create an airstream into thefoam generator 34. The front portion or front tubular section 40 of thefoam generator will have a venturi effect creating an area of high airvelocity and low pressure at the point the foamable liquid isdistributed by the distributor 32 into the airstream.

Interior flange 42 is located in the section 40 to the rear of thedistributor 32. The flange 42 disrupts the smooth flow of the aircausing a condition of extreme turbulence and high pressure between thedistributor 32 and the flange 42. in this portion of the tubular frontsection 40 there is a turbulent area or mixing chamber where the liquidand the air are thoroughly and completely mixed together thus creatingfoam.

After the foam has been thoroughly created and mixed within the foamingarea or section 40, the foam passes through the flange 42 into thedistribution section or second section 44 of the foam generator 34. Thedistribution section 44 is an airfoil section having a convex exterior,both on top and bottom. As is well known in aeronautical arts, this willcause a low pressure area on the top and bottom section 44. I haveplaced small holes or perforations 46 at this low pressure area. Becauseof the small size of the perforations and the high wind velocity, veryfine globules of foam will be dispersed from this area. Also, i haveplaced cleanout holes 48 in the leading edge 50 of the airfoil section44. When the foaming liquid valve 26 is turned off and the liquid ceasedto be sprayed into the foam chamber, the incoming air through thecleanout holes 48 quickly will blow all foam in the distribution section44 of the foam chamber 34 out, cleaning it completely.

The rear or trailing edge 51 of the section 44 has open slot ordistributing nozzle 52 across the entire width thereof. The majorportion of the foam within section 44 will be discharged through thisslot 52 can be enlarged or reduced. Also, the trailing edge of the upperand lower portion can both be bent down, causing an area of turbulencewhich will greatly tend to break up the globules of foam. Thus I haveprovided a large degree of adjustment for the globule size of foamdischarged from the nozzle or slot 52. Also, the globule size may beadjusted by changing the attitude or relationship of the entire foamgenerator 34 to the air stream. Bending the connection of the spraynozzle 28 to the boom 20 will change the relationship of the air streampassin over the airfoil 44 and therefore, wil greatly affect the size 0globules distributed from slot 52. Furthermore, the perforations 46 maybe closed as by solder, leaving all the foam to be distributed from therear trailing nozzle 52, which, generally, will result in a largerglobule size.

As explained above, foam chambers 34 set in the tip vortex and in thepropeller vortex would be adjusted to distribute a larger globule sizethan those in the midsection of the wing in relatively clear air. Also,the foam generator 34 in the tip vortex would be adjusted to have morefluid distributed to them so that they distribute more activeingredients since the vortex will tend to distribute the lifedeterminants over a wider area from these points.

Vertical stabilizers 54 are placed on either side of the airfoil section44. These also flare out in front and back, thereby creating a venturieffect and said in the distribution pattern of the foam.

The embodiments shown and described above are only excmplary. i do notclaim to have invented all the parts, elements or steps described.Various modifications can be made in the construction, material,arrangement, and operation, and still be within the scope of myinvention. The limits of the invention and the bounds of the patentprotection are measured by and defined in the following claims. Therestrictive description and drawing of the specific example above do notpoint out what an infringement of this patent would be, but are toenable the reader to make and use the invention.

I claim as my invention:

l. A foam generator comprising a. tubular chamber,

b. means for creating an airstream through said tubular chamber,

c. said chamber being open on two opposite ends,

d. a spray nozzle attached to the chamber at one of said openings tosaid tubular chamber,

e. said opening containing the spray nozzle being designated the mouth,

f. a source of foamable liquid under pressure h. means called dispersingnozzle on the other opening for dispersing foam so generated within thechamber,

j. means between the front and rear of the chamber for creatingturbulence, thereby causing foam,

k. said dispersing nozzle being adjustable in configuration to regulatethe size of globules of foam dispersed therefrom.

2. The invention as defined in claim 7, with the additional limitationsof 0. means for adjusting the rate of flow of foamable liquid to thespray nozzle.

3. A foam generator comprising a. a tubular chamber,

b. means for creating an airstream through said tubular chamber,

c. said chamber being open on two opposite ends,

(1. a spray nozzle attached to the chamber at one of said openings tosaid tubular chamber,

e. said opening containing the spray nozzle being designated the mouth,

f. a source of foamable liquid under pressure g. fluidly connected tosaid spray nozzle,

h. means called dispersing nozzle on the other opening for dispersingfoam so generated within the chamber,

j. means between the front and rear of the chamber for creatingturbulence, thereby causing foam,

k. said dispersing nozzle being adjustable to regulate the size ofglobules of foam dispersed therefrom and in. said means for creatingturbulence being an interior

1. A foam generator comprising a. tubular chamber, b. means for creatingan airstream through said tubular chamber, c. said chamber being open ontwo opposite ends, d. a spray nozzle attached to the chamber at one ofsaid openings to said tubular chamber, e. said opening containing thespray nozzle being designated the mouth, f. a source of foamable liquidunder pressure h. means called dispersing nozzle on the other openingfor dispersing foam so generated within the chamber, j. means betweenthe front and rear of the chamber for creating turbulence, therebycausing foam, k. said dispersing nozzle being adjustable inconfiguration to regulate the size of globules of foam dispersedtherefrom.
 2. The invention as defined in claim 7, with the additionallimitations of o. means for adjusting the rate of flow of foamableliquid to the spray nozzle.
 3. A foam generator comprising a. a tubularchamber, b. means for creating an airstream through said tubularchamber, c. said chamber being open on two opposite ends, d. a spraynozzle attached to the chamber at one of said openings to said tubularchamber, e. said opening containing the spray nozzle being designatedthe mouth, f. a source of foamable liquid under pressure g. fluidlyconnected to said spray nozzle, h. means called dispersing nozzle on theother opening for dispersing foam so generated within the chamber, j.means between the front and rear of the chamber for creating turbulence,thereby causing foam, k. said dispersing nozzle being adjustable toregulate the size of globules of foam dispersed therefrom and m. saidmeans for creating turbulence being an interior flange.